Tweak pc.gfx.Shader docs.
Tweak pc.gfx.Shader docs.

maxwellalive/engine,playcanvas/engine,sereepap2029/playcanvas,shinate/engine,3DGEOM/engine,SuperStarPL/engine,guycalledfrank/engine,nizihabi/engine,sanyaade-teachings/engine,playcanvas/engine,sanyaade-teachings/engine,H1Gdev/engine,maxwellalive/engine,SuperStarPL/engine,horryq/engine-1,maxwellalive/engine,aidinabedi/playcanvas-engine,3DGEOM/engine,nizihabi/engine,MicroWorldwide/PlayCanvas,RainsSoft/engine,guycalledfrank/engine,aidinabedi/playcanvas-engine,3DGEOM/engine,horryq/engine-1,RainsSoft/engine,shinate/engine,sereepap2029/playcanvas,shinate/engine,MicroWorldwide/PlayCanvas,sanyaade-teachings/engine,nizihabi/engine,RainsSoft/engine,H1Gdev/engine,horryq/engine-1,sereepap2029/playcanvas,SuperStarPL/engine